AI agents call browser_get_html to retrieve information from Byob without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and returns HTML content from a webpage element. It performs a query operation with no side effects—it does not modify, execute, or delete anything. The blast radius is minimal: an AI agent could retrieve sensitive data visible in the DOM, but cannot alter page state or trigger external actions. This is a straightforward Read operation.
From the tool's definition Tool name 'browser_get_html' and description 'Return outerHTML (default) or innerHTML of the element matching' indicate retrieval of DOM content without modification. No verbs like 'set', 'delete', 'execute', or 'click' are present.
Attacks that exploit this kind of access
Return outerHTML (default) or innerHTML of the element matching. It is categorised as a Read tool in the Byob MCP Server, which means it retrieves data without modifying state.
Register the Byob MCP server in PolicyLayer and add a rule for browser_get_html: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Byob. Nothing to install.
browser_get_html is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the browser_get_html rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for browser_get_html. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
browser_get_html is provided by the Byob MCP server (wxtsky/byob). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.